/*
 Stream.cpp - adds parsing methods to Stream class
 Copyright (c) 2008 David A. Mellis.  All right reserved.

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 Created July 2011
 parsing functions based on TextFinder library by Michael Margolis
 */

#include "Arduino.h"
#include "Stream.h"

#define PARSE_TIMEOUT 1000  // default number of milli-seconds to wait
#define NO_SKIP_CHAR  1  // a magic char not found in a valid ASCII numeric field

// private method to read stream with timeout
int Stream::timedRead() {
	int c;
	_startMillis = millis();
	do {
		c = read();
		if (c >= 0)
			return c;
	} while (millis() - _startMillis < _timeout);
	return -1;     // -1 indicates timeout
}

// private method to peek stream with timeout
int Stream::timedPeek() {
	int c;
	_startMillis = millis();
	do {
		c = peek();
		if (c >= 0)
			return c;
	} while (millis() - _startMillis < _timeout);
	return -1;     // -1 indicates timeout
}

// returns peek of the next digit in the stream or -1 if timeout
// discards non-numeric characters
int Stream::peekNextDigit() {
	int c;
	while (1) {
		c = timedPeek();
		if (c < 0)
			return c;  // timeout
		if (c == '-')
			return c;
		if (c >= '0' && c <= '9')
			return c;
		read();  // discard non-numeric
	}
}

// Public Methods
//////////////////////////////////////////////////////////////

void Stream::setTimeout(unsigned long timeout)  // sets the maximum number of milliseconds to wait
        {
	_timeout = timeout;
}

// find returns true if the target string is found
bool Stream::find(char *target) {
	return findUntil(target, NULL);
}

// reads data from the stream until the target string of given length is found
// returns true if target string is found, false if timed out
bool Stream::find(char *target, size_t length) {
	return findUntil(target, length, NULL, 0);
}

// as find but search ends if the terminator string is found
bool Stream::findUntil(char *target, char *terminator) {
	return findUntil(target, strlen(target), terminator, strlen(terminator));
}

// reads data from the stream until the target string of the given length is found
// search terminated if the terminator string is found
// returns true if target string is found, false if terminated or timed out
bool Stream::findUntil(char *target, size_t targetLen, char *terminator, size_t termLen) {
	size_t index = 0;  // maximum target string length is 64k bytes!
	size_t termIndex = 0;
	int c;

	if (*target == 0)
		return true;   // return true if target is a null string
	while ((c = timedRead()) > 0) {

		if (c != target[index])
			index = 0; // reset index if any char does not match

		if (c == target[index]) {
			//////Serial.print("found "); Serial.write(c); Serial.print("index now"); Serial.println(index+1);
			if (++index >= targetLen) { // return true if all chars in the target match
				return true;
			}
		}

		if (termLen > 0 && c == terminator[termIndex]) {
			if (++termIndex >= termLen)
				return false;       // return false if terminate string found before target string
		} else
			termIndex = 0;
	}
	return false;
}

// returns the first valid (long) integer value from the current position.
// initial characters that are not digits (or the minus sign) are skipped
// function is terminated by the first character that is not a digit.
long Stream::parseInt() {
	return parseInt(NO_SKIP_CHAR); // terminate on first non-digit character (or timeout)
}

// as above but a given skipChar is ignored
// this allows format characters (typically commas) in values to be ignored
long Stream::parseInt(char skipChar) {
	boolean isNegative = false;
	long value = 0;
	int c;

	c = peekNextDigit();
	// ignore non numeric leading characters
	if (c < 0)
		return 0; // zero returned if timeout

	do {
		if (c == skipChar)
			; // ignore this charactor
		else if (c == '-')
			isNegative = true;
		else if (c >= '0' && c <= '9')        // is c a digit?
			value = value * 10 + c - '0';
		read();  // consume the character we got with peek
		c = timedPeek();
	} while ((c >= '0' && c <= '9') || c == skipChar);

	if (isNegative)
		value = -value;
	return value;
}

// as parseInt but returns a floating point value
float Stream::parseFloat() {
	return parseFloat(NO_SKIP_CHAR);
}

// as above but the given skipChar is ignored
// this allows format characters (typically commas) in values to be ignored
float Stream::parseFloat(char skipChar) {
	boolean isNegative = false;
	boolean isFraction = false;
	long value = 0;
	char c;
	float fraction = 1.0;

	c = peekNextDigit();
	// ignore non numeric leading characters
	if (c < 0)
		return 0; // zero returned if timeout

	do {
		if (c == skipChar)
			; // ignore
		else if (c == '-')
			isNegative = true;
		else if (c == '.')
			isFraction = true;
		else if (c >= '0' && c <= '9') {      // is c a digit?
			value = value * 10 + c - '0';
			if (isFraction)
				fraction *= 0.1;
		}
		read();  // consume the character we got with peek
		c = timedPeek();
	} while ((c >= '0' && c <= '9') || c == '.' || c == skipChar);

	if (isNegative)
		value = -value;
	if (isFraction)
		return value * fraction;
	else
		return value;
}

// read characters from stream into buffer
// terminates if length characters have been read, or timeout (see setTimeout)
// returns the number of characters placed in the buffer
// the buffer is NOT null terminated.
//
size_t Stream::readBytes(uint8_t *buffer, size_t length) {
	size_t count = 0;
	while (count < length) {
		int c = timedRead();
		if (c < 0)
			break;
		*buffer++ = (char) c;
		count++;
	}
	return count;
}

// as readBytes with terminator character
// terminates if length characters have been read, timeout, or if the terminator character  detected
// returns the number of characters placed in the buffer (0 means no valid data found)

size_t Stream::readBytesUntil(char terminator, char *buffer, size_t length) {
	if (length < 1)
		return 0;
	size_t index = 0;
	while (index < length) {
		int c = timedRead();
		if (c < 0 || c == terminator)
			break;
		*buffer++ = (char) c;
		index++;
	}
	return index; // return number of characters, not including null terminator
}

String Stream::readString() {
	String ret;
	int c = timedRead();
	while (c >= 0) {
		ret += (char) c;
		c = timedRead();
	}
	return ret;
}

String Stream::readStringUntil(char terminator) {
	String ret;
	int c = timedRead();
	while (c >= 0 && c != terminator) {
		ret += (char) c;
		c = timedRead();
	}
	return ret;
}

